Herpes simplex virus type 2 (HSV-2) infection is one of the most common sexually transmitted diseases. Following acute infection of the genital tract, the virus becomes latent and can reactivate to cause recurrent disease or be shed asymptomatically. Therefore vaccines can either be prophylactic, preventing or modifying the initial infection, or therapeutic, preventing or minimizing recurrent disease in those previously infected with HSV-2. To date neither vaccine strategy has been successful. One recent vaccine strategy utilizes DNA but this approach has not been optimized. In this application, we describe experiments designed to increase the effectiveness of HSV DNA vaccines. Because protection from both acute and recurrent HSV disease appears to be mediated by T cells, the initial aims are to evaluate HSV-2 glycoprotein B (gB) DNA vaccines targeted to the endosome/lysosome to increase MHC class II presentation and the CD4+ response (Aim 1). We also will characterize gB DNA vaccines targeted to the proteasome to increase MHC Class I presentation and the CD8+ T cell response (Aim 2). We will verify targeting, evaluate T cell responses, and assess these vaccines in our well-characterized small animal models of HSV-2 infection. In Aim 3, we will combine the best MHC class I and MHC class II targeted vaccines and evaluate their combined efficacy. In Aim 4, we will examine the effects of co-expressing gB with immune homing receptors. By targeting the antigen presenting cells to the lymph nodes we hypothesize that we will increase both the HSV-specific and innate immune response and protection. Our experience with the murine and guinea pig models as well as the virologic, clinical and immunologic endpoints make these models ideal for examining the strategies proposed. The experiments proposed will improve our understanding of the protective immune response for acute and recurrent disease, increase our knowledge of targeted DNA vectors for HSV-2 and other pathogens, and should result in improved DNA vaccines.